By far the shortest epistle & the only letter written by Paul to one single individual. Philemon was a rich Roman citizen of the City of Colosse. The church in Colosse was started by Epaphras who reached out to Philemon & was saved. Philemon used his house as a house-church. Paul wrote this epistle, an appeal to Philemon concerning Onisemus, his runaway slave who reached Rome, met Paul who was on a house arrest & shared the Gospel with him.

Paul wanted him to get right with his past as a slave & as a fugitive to demonstrate internal revolution of the heart. He sent him back to Philemon with a letter to receive Onisemus as a beloved brother in the Lord. That's something quite amazing, a Slave could never be a brother. Paul didn't promote rebellion of slaves. Christianity is never about outward rebellion but internal lasting change. 

We are slaves of sin, ran away from God. Christ calls us back & paid the debt of our sin. Now, we return back to our Master & be useful. This is a challenge to churches, to receive others whom we despised & avoided, PLEASE don't look down to those criminals before, terribly poor, uneducated because we are one in-Christ. The church is one. May God bless you & your church.